橡胶集料对混凝土抗冲磨性能的增强机理研究

Study on the strengthening mechanism of rubber aggregate on the abrasion resistance of concrete

橡胶颗粒作为集料掺入普通水泥混凝土中,使其单轴抗压强度近似直线下降,但抗冲磨强度大幅提升,其冲磨损伤机理与普通混凝土有较大不同。通过以C30强度等级的普通混凝土为对比组,并保持其他材料用量不变,仅将3 mm^5 mm粒径橡胶颗粒以等体积取代方式部分替代细骨料(砂),采用水下钢球法,研究不同掺量的橡胶集料对混凝土抗冲磨强度的影响规律,以及内在作用机理。试验结果表明:与普通混凝土相比,橡胶集料混凝土单轴抗压强度和弹性模量较低,而抗冲磨强度较高;随着橡胶集料掺量的增大,单轴抗压强度和弹性模量持续减小,而抗冲磨强度不断提高。橡胶集料与砂相比,弹性大,有效缓解了混凝土内部由水泥水化引起的温度和体积膨胀等应力集中,减少了初始裂缝;在高速水流带动钢球冲磨下,橡胶集料起到保护水泥石、延长磨耗时长,在相同冲磨时间内,减少了混凝土被磨损的质量,因而大幅改善混凝土的抗冲磨强度。

The uniaxial compressive strength of rubber particles mixed into ordinary cement concrete as aggregate decreases linearly,but the anti-punching strength increases greatly,and the mechanism of punching damage is obviously different from that of ordinary concrete.This article through to C30 strength grade of the ordinary concrete as the control group,and the dosage of other materials unchanged,only 3 mm^5 mm volume particle size of rubber particles to replace the way partly replace fine aggregate(sand),USES the method of underwater steel ball,the different dosage of rubber aggregate on concrete resistance to impact strength of the influence law of,and the inner mechanism.The test results show that the uniaxial compressive strength and elastic modulus of rubber aggregate concrete are lower than that of ordinary concrete,while the impact wear strength is higher.With the increase of rubber aggregate content,the uniaxial compressive strength and elastic modulus continue to decrease,while the anti-impact wear strength continues to increase.Compared with sand,rubber aggregate has high elasticity,which effectively alleviates the stress concentration of temperature and volume expansion caused by cement hydration in concrete and reduces the initial crack.Under the impact of high-speed water flow driving steel ball,rubber aggregate plays a role in protecting the cement stone and extending the wear time.Within the same impact and wear time,the abrasion quality of concrete is reduced and the impact and wear strength of concrete is greatly improved.